A Wearable and Wireless Instrumentation Patch for Measuring Surface Bioelectric Field Projections

When measuring surface biopotentials there exists a trade-off between the spacing of the recording and reference electrodes, the fidelity of the recorded signals, and its susceptibility to motion artifacts and electromagnetic interference. In this paper, we propose and demonstrate the functionality of a wearable instrumentation patch that instead of measuring referenced biopotentials, measures local bioelectric field projections using a combination of passive differential referencing circuits, active shielding and a wide-dynamic-range instrumentation amplifier. As a result, the instrumentation patch can track biopotentials with magnitudes ranging from 1μV to 5mV, and even in the presence of significant motion artifacts. In this paper, we demonstrate different use cases and configurations of the patch for recording electrocardiogram (ECG) and electroencephalograph (EEG).